Sergey Kononov Jun 15, 2013:

You people are right about the "lines", it was one of the caliber systems, used in Russia in pre-revolutionary times. 1 line was equal to 1/10th of an inch. Americans use decimal fractions of an inch, so 4,5 lines equals to 0.45 or .45 caliber (11,43 mm, or approximately 12 mm, as stated in text)

Shvetsova A (asker) Jun 15, 2013:

I've found that yes, "линейный" has a connection with calibre and so on, but it was a separate unit of measurment, thus it cannot be translated as "calibre".

"The 1891 Russian Mosin-Nagant rifle is known as the "three-line rifle" in Russian. "
"The Model 1891 Three-Line-Rifle, known more commonly as the Mosin-Nagant, was used by a wide variety of countries prior to and during WWI." etc.

Thank you all!

Jack Doughty Jun 15, 2013:

That's interesting I hadn't realised that .300 and 7.62 were the same. In the Second World War, the British used .303 rifles and the Americans used .300. The cartridges were quite different, probably to prevent the wrong calbre being used.

Shvetsova A (asker) Jun 15, 2013:

Olga Kuchuk, thank you very much!

Olga Kuchuk Jun 15, 2013:

It is different due to the country where the weapon originates. The USA has always called theirs "45 caliber", etc. The Germans, for example, have always used cm and mm for their weapons. The Russian Navy and Army used both. For example, знаменитая винтовка Мосина, была на вооружении русской армии с конца 19го века по Великую Отечественную Войну. Она так и называлась, "трех-линейка", это значит что калибр у нее был 3 линии, то есть 3/10 дюйма, то есть 7.62мм.

Shvetsova A (asker) Jun 15, 2013:

Why then they used previously other words to denote calibre? -> "Сначала из США было получено 2 100 винтовок системы Грина калибра 13,5 мм, изготовленных в пехотном и кавалерийском варианте." Just for a change? :( And what is then the number in the parentheses "«4,5-линейный» (12-мм)"? I am confused.

Jack Doughty Jun 15, 2013:

You're right. And anyway, this is a naval weapon, so it couldn't have anything to do with the front line.

Olga Kuchuk Jun 15, 2013:

"линейный" means the caliber of the weapon. 1 линия = 1/10th of an inch. A "4,5-линейный" is simply the caliber of the weapon, has nothing to do with the front lines.